System Voice Actions is no longer a recommended path for integrating with Assistant. Please see App Actions documentation for more information on build alternatives.

Tell Google what your app can do

Google Voice Actions let users quickly complete tasks in your app using voice commands. It's another way to drive usage of your app with Google. Users' voice and text action requests can now lead directly to your Android app, so they can get to your native mobile experiences quickly and easily.
Google Voice Actions gives you one API to support Android phones, tablets, and Android Wear watches.